The chronicity and severity of antisocial behavior in children is well documented in regard to affecting both present and future psychological, behavioral, social, psychiatric and academic adjustment. Children who manifest aggressive, acting-out, and non-compliant behaviors are "at risk" for developing more chronic and pervasive dysfunctions, typically in the form of antisocial and conduct disorders. The primary objective of this investigation is to evaluate a Cognitive-Behavioral prevention program designed to improve both short- and long-term psychiatric, psychological, emotional, behavioral, interpersonal, cognitive and academic adjustment of children identified as being "at risk" for antisocial behavior and related conduct disorders. The investigation compares the efficacy of a Combined Interpersonal Cognitive Problem Solving plus Behavioral Social Skills Training Program vs. a No-Treatment Control Group with 450 4th and 5th grade male school children who are identified as being "at risk" for developing antisocial disorders. Approximately 2,500 4th and 5th grade elementary school students will be initially screened using the Child Behavior Checklist and Classroom Adjustment Rating Scale. A multiple gating screening procedure will be utilized to identify 450 "at risk" subjects who will then be randomly assigned to one of the two conditions. The training condition will consist of 60 sessions, conducted over two school years. A comprehensive assessment battery will be utilized consisting of parent and teacher ratings, psychiatric interviews and measures of self-control, sociometric status, psychological adjustment, interpersonal functioning, delinquent behavior, substance abuse, legal contacts, problem-solving, social competency, academic achievement and school performance. Assessments will be conducted at pre, mid, and post-training and 12 and 24-month follow-up phases. Analyses will be performed to determine the short- and long-term efficacy of the Cognitive Behavioral prevention program and its impact, durability, generalizability, and potency in reducing the subsequent incidence of antisocial and conduct disorders and examine mediating factors including parental psychopathology, family discord/harmony, child-rearing practices and social cognition.